The Experts below are selected from a list of 1983 Experts worldwide ranked by ideXlab platform
Klaus Peter Adam - One of the best experts on this subject based on the ideXlab platform.
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biosynthesis of the irregular monoterpene artemisia ketone the sesquiterpene germacrene d and other isoprenoids in tanacetum vulgare l asteraceae
Phytochemistry, 2004Co-Authors: Dirk Umlauf, Josef Zapp, Hans Becker, Klaus Peter AdamAbstract:The incorporation of [1-13C]-labeled glucose into the irregular monoterpene artemisia ketone, the regular monoterpenes camphor and beta-thujone, the sesquiterpene germacrene D, the diterpene trans-phytol and beta-sitosterol and isofucosterol has been studied in axenic cultures of Tanacetum vulgare L. (Asteraceae). Quantitative 13C NMR spectroscopic analysis of the resulting labeling patterns showed that the isoprene units of the monoterpenes and the diterpene are formed via the methylerythritol phosphate (MEP) pathway, whereas the isoprene building blocks of the sesquiterpene and the sterols originate from the Mevalonic Acid (MVA) pathway.
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biosynthesis of the irregular monoterpene artemisia ketone the sesquiterpene germacrene d and other isoprenoids in tanacetum vulgare l asteraceae
Phytochemistry, 2004Co-Authors: Dirk Umlauf, Josef Zapp, Hans Becker, Klaus Peter AdamAbstract:Abstract The incorporation of [1- 13 C]-labeled glucose into the irregular monoterpene artemisia ketone, the regular monoterpenes camphor and β-thujone, the sesquiterpene germacrene D, the diterpene trans -phytol and β-sitosterol and isofucosterol has been studied in axenic cultures of Tanacetum vulgare L. (Asteraceae). Quantitative 13 C NMR spectroscopic analysis of the resulting labeling patterns showed that the isoprene units of the monoterpenes and the diterpene are formed via the methylerythritol phosphate (MEP) pathway, whereas the isoprene building blocks of the sesquiterpene and the sterols originate from the Mevalonic Acid (MVA) pathway.
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biosynthesis of a hopane triterpene and three diterpenes in the liverwort fossombronia alaskana
Phytochemistry, 2001Co-Authors: Ursula Maria Hertewich, Hans Becker, Josef Zapp, Klaus Peter AdamAbstract:The biosynthesis of the triterpene 22-(30)-hopene-29-Acid and the diterpenes 7,17-sacculatadiene-11,12-dial (sacculatal), trans-phytol and a new neoverrucosane-type diterpenoid (5-oxo-neoverrucos-(13)-ene) was studied by incorporation of [1-13C]-labelled glucose into axenic cultures of the artic liverwort Fossombronia alaskana. Quantitative 13C NMR spectroscopic analysis of the resulting labelling patterns showed that the isoprene units of the triterpene are derived from the Mevalonic Acid pathway, whereas the isoprene units of the diterpenes are built up via the methylerythritol phosphate pathway.
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biosynthesis of the hemi and monoterpene moieties of isoprenyl phenyl ethers from the liverwort trichocolea tomentella
Phytochemistry, 2001Co-Authors: Anna J Barlow, Hans Becker, Klaus Peter AdamAbstract:The incorporation of 13C labelled glucose into trichocolein, deoxytomentellin, trans-phytol and stigmasterol has been studied in axenic cultures of the liverwort Trichocolea tomentella. Quantitative 13C NMR spectroscopic analysis of the resulting labelling patterns showed that the isoprene units of the hemi- and monoterpenoid moieties and the diterpene phytol are derived from the methylerythritol phosphate pathway, whereas the isoprene units of stigmasterol are built up via the Mevalonic Acid pathway. These results indicate the involvement of both IPP biosynthetic pathways in different cellular compartments. A new, hydroperoxy geranyl phenyl ether derivative is also described.
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Biosynthesis of the isoprene units of chamomile sesquiterpenes
Phytochemistry, 1998Co-Authors: Klaus Peter Adam, Josef ZappAbstract:Chamomile sesquiterpenes were labelled with13C by injection of an [I-13C]glucose solution into the anthodia of the plant. The sesquiterpenes bisabololoxide A and chamazulene were isolated from the hydrodistillate of the labelled flowers. Analysis of the labelling patterns and absolute13C abundances using quantitative13C NMR spectroscopy showed that two of the isoprene building blocks were predominantly formed via the new triose/pyruvate pathway, whereas the third unit was of mixed origin, being derived from both the Mevalonic Acid pathway and the triose/pyruvate pathway.
Daisy B Whigan - One of the best experts on this subject based on the ideXlab platform.
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liquid chromatography tandem mass spectrometry methods for quantitation of Mevalonic Acid in human plasma and urine method validation demonstration of using a surrogate analyte and demonstration of unacceptable matrix effect in spite of use of a stable isotope analog internal standard
Rapid Communications in Mass Spectrometry, 2003Co-Authors: Mohammed Jemal, Alan Schuster, Daisy B WhiganAbstract:Selective, accurate, and reproducible liquid chromatography/tandem mass spectrometry (LC/MS/MS) methods were developed and validated for the determination of Mevalonic Acid, an intermediate in the biosynthesis of cholesterol and therefore a useful biomarker in the development of cholesterol lowering drugs, in human plasma and urine. A hepta-deuterated analog of Mevalonic Acid was used as the internal standard. For both methods, calibration standards were prepared in water, instead of human plasma and urine, due to unacceptably high levels of endogenous Mevalonic Acid. The lower quality control (QC) samples were prepared in water while the higher QC samples were prepared in the biological matrices. For the isolation/purification of Mevalonic Acid from the plasma and urine matrices, the samples were first Acidified to convert the Acid analyte into its lactone form. For the plasma samples, the lactone analyte was retained on and then eluted off a polymeric solid-phase extraction (SPE) sorbent. For the urine method, the sample containing the lactone analyte was passed through a C-18 SPE column, which did not retain the analyte, with the subsequent analyte retention on and then elution off a polymeric SPE sorbent. Chromatographic separation was achieved isocratically on a polar-endcapped C-18 analytical column with a water/methanol mobile phase containing 0.5 mM formic Acid. Detection was by negative-ion electrospray tandem mass spectrometry. The standard curve range was 0.500–20.0 ng/mL for the plasma method and 25.0–1000 ng/mL for the urine method. Excellent accuracy and precision were obtained for both methods at all concentration levels tested. It was interesting to note that for certain batches of urine, when a larger sample volume was used for analysis, a high degree of matrix effect was observed which resulted not only in the attenuation of the absolute response, but also in a change of analyte/internal standard response ratio. This demonstrated that, under certain conditions, the use of a stable isotope analog internal standard does not, contrary to conventional thinking, guarantee the constancy of the analyte/internal response ratio, which is a prerequisite for a rugged bioanalytical method. On the other hand, under conditions where the sample matrix does not have such a deleterious effect, we have found that a stable isotope analog could serve as a surrogate (substitute) analyte. Thus, we have shown that using calibration standards prepared by spiking plasma with tri-deuterated or tetra-deuterated Mevalonic Acid, instead of Mevalonic Acid itself (the analyte), plasma QC samples that contain Mevalonic Acid can be successfully analyzed for the accurate and precise quantitation of Mevalonic Acid. The use of a surrogate analyte provides the opportunity to gauge the daily performance of the method for the low concentration levels prepared in the biological matrix, which otherwise is not achievable because of the endogenous concentrations of the analyte in the biological matrices. Copyright © 2003 John Wiley & Sons, Ltd.
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liquid chromatography tandem mass spectrometry methods for quantitation of Mevalonic Acid in human plasma and urine method validation demonstration of using a surrogate analyte and demonstration of unacceptable matrix effect in spite of use of a stable isotope analog internal standard
Rapid Communications in Mass Spectrometry, 2003Co-Authors: Mohammed Jemal, Alan Schuster, Daisy B WhiganAbstract:Selective, accurate, and reproducible liquid chromatography/tandem mass spectrometry (LC/MS/MS) methods were developed and validated for the determination of Mevalonic Acid, an intermediate in the biosynthesis of cholesterol and therefore a useful biomarker in the development of cholesterol lowering drugs, in human plasma and urine. A hepta-deuterated analog of Mevalonic Acid was used as the internal standard. For both methods, calibration standards were prepared in water, instead of human plasma and urine, due to unacceptably high levels of endogenous Mevalonic Acid. The lower quality control (QC) samples were prepared in water while the higher QC samples were prepared in the biological matrices. For the isolation/purification of Mevalonic Acid from the plasma and urine matrices, the samples were first Acidified to convert the Acid analyte into its lactone form. For the plasma samples, the lactone analyte was retained on and then eluted off a polymeric solid-phase extraction (SPE) sorbent. For the urine method, the sample containing the lactone analyte was passed through a C-18 SPE column, which did not retain the analyte, with the subsequent analyte retention on and then elution off a polymeric SPE sorbent. Chromatographic separation was achieved isocratically on a polar-endcapped C-18 analytical column with a water/methanol mobile phase containing 0.5 mM formic Acid. Detection was by negative-ion electrospray tandem mass spectrometry. The standard curve range was 0.500-20.0 ng/mL for the plasma method and 25.0-1,000 ng/mL for the urine method. Excellent accuracy and precision were obtained for both methods at all concentration levels tested. It was interesting to note that for certain batches of urine, when a larger sample volume was used for analysis, a high degree of matrix effect was observed which resulted not only in the attenuation of the absolute response, but also in a change of analyte/internal standard response ratio. This demonstrated that, under certain conditions, the use of a stable isotope analog internal standard does not, contrary to conventional thinking, guarantee the constancy of the analyte/internal response ratio, which is a prerequisite for a rugged bioanalytical method. On the other hand, under conditions where the sample matrix does not have such a deleterious effect, we have found that a stable isotope analog could serve as a surrogate (substitute) analyte. Thus, we have shown that using calibration standards prepared by spiking plasma with tri-deuterated or tetra-deuterated Mevalonic Acid, instead of Mevalonic Acid itself (the analyte), plasma QC samples that contain Mevalonic Acid can be successfully analyzed for the accurate and precise quantitation of Mevalonic Acid. The use of a surrogate analyte provides the opportunity to gauge the daily performance of the method for the low concentration levels prepared in the biological matrix, which otherwise is not achievable because of the endogenous concentrations of the analyte in the biological matrices.
Diana Bahia - One of the best experts on this subject based on the ideXlab platform.
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molecular characterization of trypanosoma evansi mevalonate kinase temvk
Frontiers in Cellular and Infection Microbiology, 2018Co-Authors: Daniel Pereira Duarte, Eden Ramalho Ferreira, Fabio Mitsuo Lima, Franciane Batista, Michel De Groote, E Horjales, Luiz Claudio Miletti, Diana BahiaAbstract:The mevalonate pathway, present in eukaryotes, archaea, and some bacteria, is an essential part of isoprenoid biosynthesis leading to production of isoprenoids, a diverse class of >30,000 biomolecules including cholesterol, heme, and all steroid hormones. Isoprenoid biosynthesis involves one of the most highly regulated enzymes in nature, 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), which catalyzes conversion of HMG-CoA to Mevalonic Acid. The enzyme mevalonate kinase (MVK) subsequently converts Mevalonic Acid to 5-phosphoMevalonic Acid. Trypanosoma evansi is a flagellate protozoan parasite that causes the disease “Surra” in domesticated large mammals, with great economic impact. T. evansi has only a trypomastigote bloodstream form, and requires constant modification of the VSG (variant surface glycoprotein) coat for protection against the host immune system. We characterized the MVK of T. evansi (termed TeMVK) at molecular, biochemical, and cellular levels. TeMVK from parasite extract had molecular weight ~36 KDa, was colocalized with aldolase (a glycosomal marker enzyme) in glycosomes, and was structurally similar to Leishmania major MVK. Interestingly, the active form of TeMVK was the tetrameric oligomer form, in contrast to other MVKs in which the dimeric form is active. TeMVK was detected in parasites isolated directly from mice and was colocalized with aldolase in glycosomes. Despite lacking organized mitochondria, T. evansi synthesizes both HMGCR transcripts and protein. The mevalonate pathway also generates dolichols, which play an essential role in construction of glycosylphosphatidylinositol (GPI) anchors, and VSGs are attached to the plasma membrane via GPI anchors. MVK and HMGCR in T. evansi are therefore potentially useful targets for therapeutic drug design.
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Molecular Characterization of Trypanosoma evansi Mevalonate Kinase (TeMVK)
Frontiers Media S.A., 2018Co-Authors: Daniel Pereira Duarte, Eden Ramalho Ferreira, Fabio Mitsuo Lima, Franciane Batista, Michel De Groote, E Horjales, Luiz Claudio Miletti, Diana BahiaAbstract:The mevalonate pathway is an essential part of isoprenoid biosynthesis leading to production of a diverse class of >30,000 biomolecules including cholesterol, heme, and all steroid hormones. In trypanosomatids, the mevalonate pathway also generates dolichols, which play an essential role in construction of glycosylphosphatidylinositol (GPI) molecules that anchor variable surface proteins (VSGs) to the plasma membrane. Isoprenoid biosynthesis involves one of the most highly regulated enzymes in nature, 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), which catalyzes the conversion of HMG-CoA to Mevalonic Acid. The enzyme mevalonate kinase (MVK) subsequently converts Mevalonic Acid to 5-phosphoMevalonic Acid. Trypanosoma evansi is a flagellate protozoan parasite that causes the disease “Surra” in domesticated large mammals, with great economic impact. T. evansi has only a trypomastigote bloodstream form and requires constant modification of the variant surface glycoprotein (VSG) coat for protection against the host immune system. We identified MVK of T. evansi (termed TeMVK) and performed a preliminary characterization at molecular, biochemical, and cellular levels. TeMVK from parasite extract displayed molecular weight ~36 kDa, colocalized with aldolase (a glycosomal marker enzyme) in glycosomes, and is structurally similar to Leishmania major MVK. Interestingly, the active form of TeMVK is the tetrameric oligomer form, in contrast to other MVKs in which the dimeric form is active. Despite lacking organized mitochondria, T. evansi synthesizes both HMGCR transcripts and protein. Both MVK and HMGCR are expressed in T. evansi during the course of infection in animals, and therefore are potential targets for therapeutic drug design
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Image_1_Molecular Characterization of Trypanosoma evansi Mevalonate Kinase (TeMVK).TIF
2018Co-Authors: Daniel Pereira Duarte, Eden Ramalho Ferreira, Fabio Mitsuo Lima, Franciane Batista, Michel De Groote, E Horjales, Luiz Claudio Miletti, Diana BahiaAbstract:The mevalonate pathway is an essential part of isoprenoid biosynthesis leading to production of a diverse class of >30,000 biomolecules including cholesterol, heme, and all steroid hormones. In trypanosomatids, the mevalonate pathway also generates dolichols, which play an essential role in construction of glycosylphosphatidylinositol (GPI) molecules that anchor variable surface proteins (VSGs) to the plasma membrane. Isoprenoid biosynthesis involves one of the most highly regulated enzymes in nature, 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), which catalyzes the conversion of HMG-CoA to Mevalonic Acid. The enzyme mevalonate kinase (MVK) subsequently converts Mevalonic Acid to 5-phosphoMevalonic Acid. Trypanosoma evansi is a flagellate protozoan parasite that causes the disease “Surra” in domesticated large mammals, with great economic impact. T. evansi has only a trypomastigote bloodstream form and requires constant modification of the variant surface glycoprotein (VSG) coat for protection against the host immune system. We identified MVK of T. evansi (termed TeMVK) and performed a preliminary characterization at molecular, biochemical, and cellular levels. TeMVK from parasite extract displayed molecular weight ~36 kDa, colocalized with aldolase (a glycosomal marker enzyme) in glycosomes, and is structurally similar to Leishmania major MVK. Interestingly, the active form of TeMVK is the tetrameric oligomer form, in contrast to other MVKs in which the dimeric form is active. Despite lacking organized mitochondria, T. evansi synthesizes both HMGCR transcripts and protein. Both MVK and HMGCR are expressed in T. evansi during the course of infection in animals, and therefore are potential targets for therapeutic drug design.
Mohammed Jemal - One of the best experts on this subject based on the ideXlab platform.
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liquid chromatography tandem mass spectrometry methods for quantitation of Mevalonic Acid in human plasma and urine method validation demonstration of using a surrogate analyte and demonstration of unacceptable matrix effect in spite of use of a stable isotope analog internal standard
Rapid Communications in Mass Spectrometry, 2003Co-Authors: Mohammed Jemal, Alan Schuster, Daisy B WhiganAbstract:Selective, accurate, and reproducible liquid chromatography/tandem mass spectrometry (LC/MS/MS) methods were developed and validated for the determination of Mevalonic Acid, an intermediate in the biosynthesis of cholesterol and therefore a useful biomarker in the development of cholesterol lowering drugs, in human plasma and urine. A hepta-deuterated analog of Mevalonic Acid was used as the internal standard. For both methods, calibration standards were prepared in water, instead of human plasma and urine, due to unacceptably high levels of endogenous Mevalonic Acid. The lower quality control (QC) samples were prepared in water while the higher QC samples were prepared in the biological matrices. For the isolation/purification of Mevalonic Acid from the plasma and urine matrices, the samples were first Acidified to convert the Acid analyte into its lactone form. For the plasma samples, the lactone analyte was retained on and then eluted off a polymeric solid-phase extraction (SPE) sorbent. For the urine method, the sample containing the lactone analyte was passed through a C-18 SPE column, which did not retain the analyte, with the subsequent analyte retention on and then elution off a polymeric SPE sorbent. Chromatographic separation was achieved isocratically on a polar-endcapped C-18 analytical column with a water/methanol mobile phase containing 0.5 mM formic Acid. Detection was by negative-ion electrospray tandem mass spectrometry. The standard curve range was 0.500–20.0 ng/mL for the plasma method and 25.0–1000 ng/mL for the urine method. Excellent accuracy and precision were obtained for both methods at all concentration levels tested. It was interesting to note that for certain batches of urine, when a larger sample volume was used for analysis, a high degree of matrix effect was observed which resulted not only in the attenuation of the absolute response, but also in a change of analyte/internal standard response ratio. This demonstrated that, under certain conditions, the use of a stable isotope analog internal standard does not, contrary to conventional thinking, guarantee the constancy of the analyte/internal response ratio, which is a prerequisite for a rugged bioanalytical method. On the other hand, under conditions where the sample matrix does not have such a deleterious effect, we have found that a stable isotope analog could serve as a surrogate (substitute) analyte. Thus, we have shown that using calibration standards prepared by spiking plasma with tri-deuterated or tetra-deuterated Mevalonic Acid, instead of Mevalonic Acid itself (the analyte), plasma QC samples that contain Mevalonic Acid can be successfully analyzed for the accurate and precise quantitation of Mevalonic Acid. The use of a surrogate analyte provides the opportunity to gauge the daily performance of the method for the low concentration levels prepared in the biological matrix, which otherwise is not achievable because of the endogenous concentrations of the analyte in the biological matrices. Copyright © 2003 John Wiley & Sons, Ltd.
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liquid chromatography tandem mass spectrometry methods for quantitation of Mevalonic Acid in human plasma and urine method validation demonstration of using a surrogate analyte and demonstration of unacceptable matrix effect in spite of use of a stable isotope analog internal standard
Rapid Communications in Mass Spectrometry, 2003Co-Authors: Mohammed Jemal, Alan Schuster, Daisy B WhiganAbstract:Selective, accurate, and reproducible liquid chromatography/tandem mass spectrometry (LC/MS/MS) methods were developed and validated for the determination of Mevalonic Acid, an intermediate in the biosynthesis of cholesterol and therefore a useful biomarker in the development of cholesterol lowering drugs, in human plasma and urine. A hepta-deuterated analog of Mevalonic Acid was used as the internal standard. For both methods, calibration standards were prepared in water, instead of human plasma and urine, due to unacceptably high levels of endogenous Mevalonic Acid. The lower quality control (QC) samples were prepared in water while the higher QC samples were prepared in the biological matrices. For the isolation/purification of Mevalonic Acid from the plasma and urine matrices, the samples were first Acidified to convert the Acid analyte into its lactone form. For the plasma samples, the lactone analyte was retained on and then eluted off a polymeric solid-phase extraction (SPE) sorbent. For the urine method, the sample containing the lactone analyte was passed through a C-18 SPE column, which did not retain the analyte, with the subsequent analyte retention on and then elution off a polymeric SPE sorbent. Chromatographic separation was achieved isocratically on a polar-endcapped C-18 analytical column with a water/methanol mobile phase containing 0.5 mM formic Acid. Detection was by negative-ion electrospray tandem mass spectrometry. The standard curve range was 0.500-20.0 ng/mL for the plasma method and 25.0-1,000 ng/mL for the urine method. Excellent accuracy and precision were obtained for both methods at all concentration levels tested. It was interesting to note that for certain batches of urine, when a larger sample volume was used for analysis, a high degree of matrix effect was observed which resulted not only in the attenuation of the absolute response, but also in a change of analyte/internal standard response ratio. This demonstrated that, under certain conditions, the use of a stable isotope analog internal standard does not, contrary to conventional thinking, guarantee the constancy of the analyte/internal response ratio, which is a prerequisite for a rugged bioanalytical method. On the other hand, under conditions where the sample matrix does not have such a deleterious effect, we have found that a stable isotope analog could serve as a surrogate (substitute) analyte. Thus, we have shown that using calibration standards prepared by spiking plasma with tri-deuterated or tetra-deuterated Mevalonic Acid, instead of Mevalonic Acid itself (the analyte), plasma QC samples that contain Mevalonic Acid can be successfully analyzed for the accurate and precise quantitation of Mevalonic Acid. The use of a surrogate analyte provides the opportunity to gauge the daily performance of the method for the low concentration levels prepared in the biological matrix, which otherwise is not achievable because of the endogenous concentrations of the analyte in the biological matrices.
Josef Zapp - One of the best experts on this subject based on the ideXlab platform.
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biosynthesis of the irregular monoterpene artemisia ketone the sesquiterpene germacrene d and other isoprenoids in tanacetum vulgare l asteraceae
Phytochemistry, 2004Co-Authors: Dirk Umlauf, Josef Zapp, Hans Becker, Klaus Peter AdamAbstract:The incorporation of [1-13C]-labeled glucose into the irregular monoterpene artemisia ketone, the regular monoterpenes camphor and beta-thujone, the sesquiterpene germacrene D, the diterpene trans-phytol and beta-sitosterol and isofucosterol has been studied in axenic cultures of Tanacetum vulgare L. (Asteraceae). Quantitative 13C NMR spectroscopic analysis of the resulting labeling patterns showed that the isoprene units of the monoterpenes and the diterpene are formed via the methylerythritol phosphate (MEP) pathway, whereas the isoprene building blocks of the sesquiterpene and the sterols originate from the Mevalonic Acid (MVA) pathway.
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biosynthesis of the irregular monoterpene artemisia ketone the sesquiterpene germacrene d and other isoprenoids in tanacetum vulgare l asteraceae
Phytochemistry, 2004Co-Authors: Dirk Umlauf, Josef Zapp, Hans Becker, Klaus Peter AdamAbstract:Abstract The incorporation of [1- 13 C]-labeled glucose into the irregular monoterpene artemisia ketone, the regular monoterpenes camphor and β-thujone, the sesquiterpene germacrene D, the diterpene trans -phytol and β-sitosterol and isofucosterol has been studied in axenic cultures of Tanacetum vulgare L. (Asteraceae). Quantitative 13 C NMR spectroscopic analysis of the resulting labeling patterns showed that the isoprene units of the monoterpenes and the diterpene are formed via the methylerythritol phosphate (MEP) pathway, whereas the isoprene building blocks of the sesquiterpene and the sterols originate from the Mevalonic Acid (MVA) pathway.
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biosynthesis of a hopane triterpene and three diterpenes in the liverwort fossombronia alaskana
Phytochemistry, 2001Co-Authors: Ursula Maria Hertewich, Hans Becker, Josef Zapp, Klaus Peter AdamAbstract:The biosynthesis of the triterpene 22-(30)-hopene-29-Acid and the diterpenes 7,17-sacculatadiene-11,12-dial (sacculatal), trans-phytol and a new neoverrucosane-type diterpenoid (5-oxo-neoverrucos-(13)-ene) was studied by incorporation of [1-13C]-labelled glucose into axenic cultures of the artic liverwort Fossombronia alaskana. Quantitative 13C NMR spectroscopic analysis of the resulting labelling patterns showed that the isoprene units of the triterpene are derived from the Mevalonic Acid pathway, whereas the isoprene units of the diterpenes are built up via the methylerythritol phosphate pathway.
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Biosynthesis of the isoprene units of chamomile sesquiterpenes
Phytochemistry, 1998Co-Authors: Klaus Peter Adam, Josef ZappAbstract:Chamomile sesquiterpenes were labelled with13C by injection of an [I-13C]glucose solution into the anthodia of the plant. The sesquiterpenes bisabololoxide A and chamazulene were isolated from the hydrodistillate of the labelled flowers. Analysis of the labelling patterns and absolute13C abundances using quantitative13C NMR spectroscopy showed that two of the isoprene building blocks were predominantly formed via the new triose/pyruvate pathway, whereas the third unit was of mixed origin, being derived from both the Mevalonic Acid pathway and the triose/pyruvate pathway.